You may encounter this message while connecting to a remote server through ssh.
Generally, you also have these lines :
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
To prevent from having this error again, there are solutions :
1) Edit the following line ~/.ssh/known_hosts and remove the line containing the hostname of the remote server in question.
2) Sometime, the file ~/.ssh/known_hosts may be hashed. To regenerate the key properly,as a non-root user, please type the following command :
fool@localhost:~$ ssh-keygen -R hostname